As expected, CD8 T cell responses targeting the five epitopes that were ablated in m3KOΔnef were undetectable at 3 weeks after m3KOΔnef infection, as measured by IFN-γ ELISPOT assays with PBMCs and tetramer staining of cells isolated from lymph nodes (Fig. 4 and 5D). Here, CD8A is linked to infection.